body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}
#app {
    width: 300px;
    background: #fff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    overflow: hidden;
}
.header {
    background: #2c3e50;
    color: #fff;
    padding: 16px;
    text-align: center;
    border-bottom: 1px solid #ddd;
}
.header h1 {
    margin: 0;
    font-size: 24px;
}
.header .new-todo {
    width: 70%;
    padding: 10px;
    border: none;
    border-radius: 4px;
    margin-right: 10px;
}
.header .add {
    padding: 10px 20px;
    background: #3498db;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}
.header .add:hover {
    background: #2980b9;
}
.main {
    padding: 16px;
}
.todo-list {
    list-style: none;
    padding: 0;
    margin: 0;
}
.todo {
    position: relative;
    padding: 12px 0;
    border-bottom: 1px solid #ddd;
}
.todo:last-child {
    border-bottom: none;
}
.todo .index {
    color: #999;
    margin-right: 10px;
}
.todo label {
    font-size: 16px;
    cursor: pointer;
}
.todo .destroy {
    position: absolute;
    top: 50%;
    right: 10px;
    transform: translateY(-50%);
    background: none;
    border: none;
    font-size: 18px;
    color: #e74c3c;
    cursor: pointer;
}
.footer {
    background: #ecf0f1;
    padding: 16px;
    text-align: center;
    border-top: 1px solid #ddd;
}
.footer .todo-count {
    font-weight: bold;
    color: #333;
}
.footer .clear-completed {
    margin-left: 10px;
    padding: 10px 20px;
    background: #e74c3c;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}
.footer .clear-completed:hover {
    background: #c0392b;
}